Big SUV or truck

Looking for a tow vehicle for our new trailer. 5500# GVWR and tongue weight is around 650# loaded but may be more if we add bikes in our internal bike storage area.

I've got 4 options I'm considering:
1. Buy a 2014 F-150 with EcoBoost engine to replace our MDX
2. Buy a large SUV - Expedition, Sequoia, Armada, etc. to replace our MDX
3. Buy a cheap (8K or less), old truck to tow and keep using our MDX for daily driving
4. Rent a truck to tow for our 3-4 trips planned this summer and figure it all out next summer

Problems with the options:
1. Storage in truck difficult for groceries, stroller, kids day to day backpacks, dance bags, etc. And the expense of a new vehicle. And the truck is HUGE. Only a few inches on either side to get through garage door (hopefully the power fold mirrors are easy to use?) and probably a foot and half length to spare. So difficult for kids to walk around to get from house and into house, etc.
2. More expensive than the F-150 which has great employee pricing right now. Worse gas mileage than the F-150.
3. Potential maintenance costs and problems, likely can't get a super crew to hold the whole family (have rear facing car seats) so would need to take 2 vehicles every time
4. Expense of renting, having trouble finding a place that will rent trucks around me, and may involve taking 2 vehicles still as the one place I found so far doesn't have the super crews

Anyone been there, done that, or have any opinions?